Olurotimi,
I agree with Harry. If anything, become familiar with the earned value formulas in the PMBOK Guide 6th edition, and know how to interpret the results. Chances are you won't get a question that asks to calculate something, but rather the question will assess your behaviour given a scenario in which a certain earned value metric is at a certain number. Hope this makes sense.
All the best in your studies, and I'm sure you will do great!
Cheers,